1. Field of the Invention
The present invention relates to a router system, and more particularly to router system duplicating a forwarding-engine and a method of duplicating a forwarding engine.
2. Description of the Related Art
Generally, data communication networks install multiple router systems for transmitting data to destination networking components such as subscribers, switchboards, or networks, according to routing information of the transmission data.
The conventional router system includes a routing controller called a router server, a forwarding engine, a switch fabric, and other components. The router server is a main controller of a router system performing functions of creating routing information, such as a routing table and a forwarding table by operating a routing protocol. The forwarding engine forwards an Internet protocol IP packet based on the forwarding table created in the routing controller. The switch fabric transmits data among the forwarding engines. In other words, the switch fabric transmits data within the router system.
As described in the above statements, each component of the conventional router system is duplicated to cope with various possible troubles according to the situations, such as physical damage in instruments, errors in software, or abnormal data transmission, etc., and thereof to ensure operational reliability.
The conventional duplication method can duplicate extremely limited number, in other words, one or a few, routing controller, switching fabric, and power supplier/temperature controller.
In other words, the router system simultaneously equips the main routing controller and the subordinate routing controller having the same functions with the main routing controller, or simultaneously equips the main switching fabric and the subordinate switching fabric having the same functions with the switching fabric. Therefore, when troubles happen to the switching fabric or the routing controller, the corresponding subordinate systems are operated to substitute the functions and to repair the troubled systems.
The conventional duplication method has difficulties in duplicating the forwarding engines, because many forwarding engines are generally installed within the router system. In other words, many of subordinate forwarding engines are required to substitute for the many forwarding engines according to the conventional duplication method.
However, in the above cases, the router system becomes very expensive to install multiple subordinate forwarding engines. Therefore, it is hard to embody such a router system actually because it is uneconomical.
Additionally, even though subordinate forwarding engines are installed without considering economical problems, additional subordinate forwarding engines are necessary when the router system is expanded. Therefore, the expandability and the flexibility of the router system are debased.
As described in the above statement, the conventional duplication method is hard to provide successful duplicated router system, especially successful duplicated forwarding engines. Therefore, it is necessary to provide a router system and a method of duplicating forwarding engines efficiently through another configurations, and without installing multiple subordinate forwarding engines to the corresponding forwarding engines.
Additionally, according to capacity expansions in each of the forwarding engines due to expansions of data communication demands, the forwarding engines are more important than ever. As a result, successful duplication of the forwarding engines is more requested.